Comminutor



June 29, 1943. c, w, HASE 2,322,922

COMMINUTOR Filed Feb. 26, 1940 3 Sheets-Sheet l June 29, 1943. c. w.CHASE 2,322,922

COMMINUTOR Filed Feb. 26, 1940 3 Sheefcs-Sheet 2 l io I a i 0 o m k i 1;23K". 9 24 1 9 6 .15 i o "a m 37, z .254 17 i 1 o W 9 I g Q a e o 18 ii9 w i o '5; m 229 6 M I a a I o i n? fi-TF'T L Z 0 IQ weld (917 June 29,1943.

3 Sheets-Sheet 3 33 6 Jjaw/ezotw CawmZdCMae Patented June 29, 1943UNITED STATES PATENT OFFICE COMMINUTOR Corson W. Chase, Chicago, 11].,assignor to Chicago Pump Company, Chicago, Ill., a. corporation ofIllinois Application February 26, 1940, Serial No. 320,865 reclaims.(Cl. 210-152) the copending application of Augustus C. Durdin,

III, Serial No. 155,710, filed July 26, 19-37.

The principal object of the invention is to provide an improvedcomminutor of this general typ A further object of the invention is toprovide a comminutor of this type in which the cutting load issubstantially uniform.

A further object of the invention is to provide improved stationarycutter means whereby replacements and repairs may be made moreeconomically.

A further object of the invention is to provide improved cutting meanswhereby the screen may be cleaned automatically in the normal operationof the comminutor. 1

A further object of the invention is to provide in a comminutor of thistype cutting means adapted to expel metal objects such as spikes andnails, without expelling softer materials such as wood and non-metallicdebris generally Other objects, advantages and capabilities of theinvention will appear from the following description of a preferredembodiment thereof, taken in conjunction with the accompanying drawings,in which:

Figure 1 is a perspective view of the improved comminutor;

Fig. 2 is an elevational view partly in section, showing the manner inwhich the screen is mounted;

Fig. 3 is a sectional detail view, taken on the line 3-3 of Fig. 1,showing a cutting bar and cutting tooth in cross-section;

Fig. 4 is a side elevation of a tooth;

Fig. 5 is a sectional plan detail, taken on the line 5-5 of Fig. 1showing the manner in which the cutting face of the tooth cooperateswith a cutting comb, and

Fig. 6 is a vertical sectional view of the comminutor screen showing theoblique relation of its supporting spokes.

Referring to the drawings and particularly to Fig. 1, my improvedcomminutor comprises a base in, a standard mounted thereon, a head l2mounted on the standard, a motor l3 mounted on the head l2 and a screenI I which is of substantially cylindrical form rotatably suspended fromthe head l2 and adapted to be driven by the motor l3. between the headI2 and the base ill, the portion of the base l0 inside the screenproviding a downward exit opening for the liquid and comminuted solids.In operation the improved com- The screen I4 extends upon the cylinderI4.

minutor is located in a suitable chamber into which the sewage isdelivered.

The screen it may suitably be in the form of a casting having an outercylindrical wall which is provided with a plurality of series ofhorizontal slots l5 through which the liquid may pass into the interiorof the screen. Each series of slots I5 is located on the cylindricalscreen in oblique relation, the series being separated by solid wallportions l6 which also extend obliquely along the length of thecylindrical wall.

The cylindrical wall of the screen is connected to a hub H by means ofenlarged spoke members III which extend obliquely relative to the axisof rotation of the screen. The outer ends of the spokes I8 extendsubstantially along the cylindrical wall and conform to the obliquerelation of the solid portions l6 of the screen with which they areintegral. The cylindrical screen is secured to a shaft I! which isdriven by the motor I! in the direction indicated by the arrow on Fig.1, the hub I'I being secured to the shaft I9. It may be noted that thesloping spokes I8 serve as vanes, forcing the liquid within the screendownwardly through the discharge opening 20 and thus minimizing theresistance to flow presented by the screen I.

The forward ends of the slots l5 of each series are preferably locatedon a straight line. The rear ends of the slots of each series terminateon a plurality of vertical lines, the forward edge of the solid portionsit of the cylindrical wall being in stepped formation as best seen in Fi1.

The standard portion II is provided with a teeth 23 which project almostinto contact with the cylindrical surface of the screen ll. These teethand the recesses between them are cutback from the front face of thecomb at suitable angles to provide cutting clearance. The forwardcutting portions of these teeth and the adjacent portions of the comb 22may suitably be formed from a strip 24 of hard cutting material, forexample, stellite, which may be secured in suitable manner to the mainportion of the comb 22'.

The forward faces of the teeth 23 are adapted to cooperate with cuttingbars 25. These cutting bars are mounted by means of suitable bolts Theyare located inslots 28 which are formed in the screen It along theforward faces of the step formations of the solid cylindrical portions13. As best seen in Fig. 1, the cutting bars 25 are arranged inoverlapping relation and they are also arranged so that each cutting barcooperates with two of the combs 22. Since the bars 25 are vertical andthe cutting combs 22 are displaced relatively with respect to thevertical direction, each cutting bar cooperates with the forward edgesof the teeth of one comb and shortly thereafter the bar cooperates withthe forward edges of cutting teeth of the next comb. Owing to therelative displacement of the combs 22' and the relative displacement ofthe bars 25, the cutting load of these bars is distributed over a wideangle of rotation of the screen H. The cutting bars 25 are mounted onthe screen 14 so that their forward edges are substantially flush withthe cylindrical surface of the screen it. They may, however, be arrangedto project slightly beyond this surface in order to cooperate moreeffectively with the outer ends of the teeth 23.

The forward edge of the cutting bar 231 may suitably consist of a stripof hard cutting material, for example, stellite, which is rigidlymounted on the main portion of the bar. It will readily be understoodthat any fibrous material which y be come caught upon the bar portionsof the screen between the slots 15 are engaged by the cutting edges ofthe teeth 23 of the combs 22, these teeth being in alignment with and inoverlapping relation to the slots 15. Such fibrous materials areconsequently carried by the teeth 23 and are severed by the cutting bars25 so that the severed portions may flow through the screen and passinto the discharge opening 20. The bars 25 are provided with tappedopenings 25' for the reception of jack screws for forcibly removing thebars from their seats 26 when desired.

Upon the cylindrical wall of the screen 14, and preferably upon thesolid portions l6 thereof, I mount a plurality of cutting teeth 21. Eachcutting tooth 21 may suitably comprise an elongated base portion 28which is formed to seat snugly within a. recess 29 formed in the outer'cylindrical surface of the screen I4. This base portion is provided witha seat 30 for the head 3| of a bolt which passes through an opening 32in the base into a threaded opening in the cylindrical wall of thescreen 14.

The opening 32 is provided with a lateral extension to facilitate theremoval of the tooth from its seat 29. The head 3| of the bolt isnormally below the surface of the cylindrical wall of the screen andwhen this bolt is removed a tool can be inserted into the lateralextension of the opening 32 so that the cutting tool 21 may be forciblywithdrawn from its seat. The cutting tooth comprises a cuttingprojection 33 which is provided with a cutting face 34 which is locatedof the screen I4. The cutting projection 33 of each tooth is adapted topass in cutting relation with the three sides of a corresponding recessbetween a pair of adjacent teeth 23 on one of the combs 22. The combsare so formed that a single recess on each comb 22 corresponds to one ofthe teeth 21. The forward face 34 of the cutting projection 33 of eachcutting tooth 21 has its outer portion in the form of a plane. Thisplane is connected by a curved face 35 which connects the plane faceinto the outer surface of the base 23.

1t is to be noted that the combs 22 are not located in radial relationto the screen M. They lie in planes which pass in front of the axis ofthe screen M. Consequently, the base of the cutting projection 33, thatis, the curved portion 35 of the front face of the projection 33, passesbetween two teeth 23, and the plane portion 34 of the cutting face ofthe projection 33 being substantially radial with respect to-the axis ofthe drum i4, moves gradually in between the adjacent teeth 23, as bestseen in Fig. 5. In other words, at the time of cutting, any radial lineon the face 34 is located at a slight angle to the outer face of thecomb 22 with which it is cooperating. In the event that relatively softmaterial such as wood is being cut, this angle is insufiicient to expelthe material engaged between the teeth and the comb. In the event,however, that a piece of metal such as a nail or spike is locatedbetween the tooth and the comb, this open angle is sufficient to causeits expulsion, thus saving the tooth from fracture. The curved faces 35aid materially in the expulsion of nails, spikes and the like out of thespace between the tooth and the comb so that the teeth are not injuredby the work otherwise necessary to sever these hard objects.

As best seen in Fig. 1, the teeth 21 are arranged in staggered relationso that, for the most part, only one tooth or, in some cases, two teethare operative at any time. Thus, in the left-hand assembly of teeth 21shown in Fig. 1, the uppermost step has three teeth 21 operative atdifferent times. The second step has fOl-lfiiififith operative atdifferent times. Two of these teeth are in vertical alignment, but theycooperate with the second and third combs 22 which are out of verticalalignment. The third step comprises three teeth 21 in verticalalignment, but the uppermost tooth cuts before the other two.

In operation, solid material carried by the incoming flow is carried upagainst the screen 14. This solid material is engaged by the teeth 21and is carried around to the combs 22. Normal solids,

including pieces of wood, are comminuted, each tooth breaking a smallportion out of the solid. These small portions are carried by the streamthrough the screen 14. In the case of a large piece of wood, forexample, the teeth 21 continuously take bites out of it until the woodis completely disintegrated into small pieces which pass through thescreen.

As previously described, nails, spikes and other metal objects which maybe carried by pieces of wood, for example, are expelled from the cuttingmembers and softer materials associated with these metal objects aredisintegrated until the expelled metal objects sink to the bottom of thechamber, from which they may be removed at suitable intervals.

The mounting of the combs 22 out of alignment and the generally obliquerelation of each group of cutting teeth 21 and their staggered relationwith their groups, distributes the cutting load substantially around thecomplete cylindrical surface of the screen 14.

Although the invention has been disclosed in connection with thespecific details of a preferred embodiment thereof, it must beunderstood that such details are not intended to be limitative of theinvention except in so far as set forth in the accompanying claims.

Having thus described my invention, what I claim as new and desire tosecure by letters Patent of the United States is:

1. A comminutor comprising a rotatable screen, cutting teeth on saidscreen, and stationary cutting comb means adapted to cooperate with saidteeth, said teeth being arranged in a plurality of 7 separate serieslocated in a generally oblique direction relative to the axis ofrotation at a plurality of positions on said screen.

2. A comminutor comprising a rotatable screen, cutting teeth on saidscreen, and stationary cutting comb means adapted to cooperate with saidteeth, said teeth being arranged in a plurality of separate serieslocated in a generally oblique direction relative to the axis ofrotation at a plurality of positions on said screen, and said cutter barmeans being arranged in an oppositely oblique relation.

3. A comminutor comprising a rotatable screen, cutting teeth on saidscreen at various locations therealong, and a series of stationarycutting combs each adapted to cooperate with a plurality of teeth, eachsaid cutting comb having a pinrality of recesses through which the teethpass in cutting relation, the adjacent ends of said cutting combs beingarranged in overlapping relation and each tooth being provided with acomplete corresponding recess in one of said combs.

4. A comminutor comprising a rotatable screen, cutting teeth on saidscreen, stationary cutting comb means provided with recesses throughwhich said cutting teeth pass in cutting relation and teeth whichproject towards said screen, and cutting bars mounted on said screenadapted to cooperate with the outermost ends of said cutting comb teeth.

5. A comminutor comprising a rotatable screen having arcuate slots forthe passage of liquid, cutting teeth mounted on said screen, stationarycutting comb means provided with recesses through which said teeth passin cutting relation and teeth which project towards said screen, andcutter bars mounted on said screen at the rear end of said slots adaptedto cooperate with the ends of said cutting comb teeth, the last saidteeth being in alignment with at least part of the surfaces of thescreenbetweensaid slots whereby material caught on said surfaces andextending into said slots is severed between the last said teeth and thecutter bars of the screen.

6. In a comminutor, in combination, a rotary screen having a cylindricalwall provided with water passing slots, a hub and spoke membersconnecting said wall to said hub, means providing an outlet from thelower end of the interior of the screen, and a shaft carrying said hub,saidspoke members being relatively long and being arranged obliquely tothe axial direction of the screen whereby they serve as pumping vanes toforce liquid downwardly through said outlet.

7. In a comminutor, in combination, a screen, a cutting bar having aseat in said screen, means securing said bar in its seat, and threadedopenings in said bar adapted to receive threaded members to serve asjacks for forcible removalof the bars from their seats.

8. A comminutor comprising a screen, a cutting comb, means for effectingrelativ movement therebetween, and cutting teeth on said screen and saidcutting comb adapted to'move past each other, said teeth being adaptedto cut at an open angle whereby hard metal objects are expelled frombetween the teeth and softer materials are retained and comminuted.

9. A comminutor comprising a screen, a cutting comb, means for effectingrelative movement therebetween, and cutting teeth on said screen andsaid cutting comb adapted to move past each other, said teeth beingadapted to cut at an open angle and certain of said teeth having anarcuate formation whereby hard metal objects are expelled from betweenthe teeth and softer materials are retained and comminuted.

, tion of said plane surface merging forwardly into the base portion.

11. A tooth for a comminutor comprising an elongated base portion and acutting portion projecting from and coextensive with one end of the baseportion, said cutting portion continuing outwardly in alignment withsaid end of the base portion, said cutting portion having a cutting facecomprising a plane surface extending across the width of the baseportion and oblique to the transverse direction of said base portion,and an arcuate surface in continuation of said plane surface mergingforwardly into the base portion.

12. A comminutor comprising two relatively movable members, cooperatingcutting teeth on said members, one of said members being provided with asurface having recessed seats therein, each tooth on last said membercomprising an elongated base portion adapted to be received within oneof said seats, and a cutting portion projecting from and coextensivewith the rear end of the base portion, said cutting portion continuingoutwardly in alignment with said end of the base portion, said cuttingportion having a cutting face comprising a plane surface substantiallytransverse to the longitudinal direction of the base portion, and anarcuate surface in continuation of said plane surface merging forwardlyinto the base portion.

13.' A comminutor comprising two relatively movable members, cooperatingcutting teeth on said members, one of said members being provided with asurface having recessed seats therein, each tooth on last said membercomprising an elongated base portion adapted to be received within oneof said seats, and a cutting portion projecting from and coextensivewith the rear end of the base portion, said cutting portion continuingoutwardly in alignment with said end of the base portion, said cuttingportion having a cutting face comprising a plane surface substantiallytransverse to the longitudinal direction 01 the base portion, and anarcuate surface in continuation of said plane surface merging forwardlyinto the base portion, the teeth on said members being arranged to movepast each other with an open angle between them.

14. A comminutor comprising a rotatable screen, cutting. teeth on saidscreen at various locations therealong, and a series of cutter combseach adapted to cooperate with a plurality of teeth, each said cuttercomb having a plurality 'of recesses through which the teeth pass incut- CORSON w. CHASE.

